Determining worker exposure to hazardous volatile organic compounds (VOCs) in air at levels exceeding the Permissible Exposure Limits and Recommended Exposure Limits established by the U.S. federal agencies of Occupational Safety and Health Administration (OSHA) and the National Institute for Occupational Safety and Health (NIOSH), respectively, will continue to be an important part of environmental and occupational health risk assessments. The purpose of this work was to develop a reliable analytical method for rapid and on-site assessments of occupational VOC exposures using field-capable thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) instrumentation (i.e. the HAPSITE ER). The experiments involved in this study included determining TD-GC-MS parameters suitable for efficient analyte separation and quantitation on the HAPSITE ER, determinations of analyte mass loadings that cause mass spectrometer detector saturations, generation of calibration curves, estimations of the limits of detection (LODs) and quantification (LOQs), as well as desorption efficiency and relative response factor repeatability. The LODs using Carbopack B and Tenax TA sampling media were estimated and ranged from 0.2-1.9 ng and 0.045-0.3 ng, respectively. The LOQs using Carbopack B and Tenax TA sampling media were estimated and ranged from 1.0-6.3 ng and 0.2-1.1 ng, respectively. We have developed a reliable analytical method for chloroform, benzene, trichloroethylene, and heptane using field-portable HAPSITE ER instrumentation and Tenax TA sorbent media. Reliable and accurate methods were developed for chloroform and trichloroethylene using Carbopack B sorbent media, however, this particular sorbent hadlow desorption efficiency and insufficient repeatability in relative response factors for many analytes. Our current and ongoing work in determining the uptake rates for analytes on Tenax TA sorbent media will make the methods described herein applicable for on-site occupational VOC exposure assessments of chloroform, benzene, trichloroethylene, and heptane using either passive or active air sampling techniques.

Constructed wetlands are an attractive choice for removing arsenic (As) within water resources used for drinking water production. The role of substrate and vegetation in As removal processes is still poorly understood. In this study, gravel, zeolite (microporous aluminosilicate mineral), ceramsite (lightweight expanded clay aggregate) and manganese sand were tested as prospective substrates while aquatic (Soft Rush or Common Rush) and terrestrial L. (Chinese Ladder Brake; known as As hyperaccumulator) were tested as potential wetland plants. Indoor batch adsorption experiments combined with outdoor column experiments were conducted to assess the As removal performances and process mechanisms. Batch adsorption results indicated that manganese sand had the maximum As(V) adsorption rate of 4.55 h and an adsorption capacity of 42.37 μg/g compared to the other three aggregates. The adsorption process followed the pseudo-first-order kinetic model and Freundlich isotherm equations better than other kinetic and isotherm models. Film-diffusion was the rate-limiting step. Mean adsorption energy calculation results indicated that chemical forces, particle diffusion and physical processes dominated As adsorption to manganese sand, zeolite and gravel, respectively. During the whole running period, manganese sand-packed wetland filters were associated with constantly 90% higher As(V) reduction of approximate 500 μg/L influent loads regardless if planted or not. The presence of contributed to no more than 13.5% of the total As removal. In contrast, was associated with a 24% As removal efficiency.

Microcystins (MCs) are widespread cyanobacterial toxins in freshwater systems, and have been linked to both acute and chronic health effects. A growing number of studies suggest that MC can bioaccumulate in food webs. Although, several methods (i.e. ELISA, LC-MS) have been developed for analysis of MC in water, extraction (for subsequent analysis) of the toxin from biological matrices (i.e. animal tissues) is impeded owing to covalent binding of toxins and active sites of their cellular targets, i.e. protein phosphatases. As an alternative approach, chromatographic methods for analysis of a unique marker, 2-methyl-3-methoxy-4-phenylbutanoic acid (MMPB), the product of the Lemieux oxidation of MCs, have been previously developed, and shown to measure total (bound and unbound) MC. Application, however, has been limited by poor recovery of the analyte. An improved recovery method is proposed - specifically the use of solidphase microextraction (SPME). The MMPB analogue, 4-phenylbutanoic acid (4PB), and oxidized MC, were used to develop methods, and we specifically investigated several SPME fibres, and post-oxidation steps. Specifically, a method employing post-oxidation methyl esterification, followed by headspace SPME recovery of MMPB, was developed, and subsequently applied to analysis of environmental samples (i.e. fish tissues) previously shown to contain MCs. The method shows high linearity for both water and tissues spiked with MC, and an improved limit of quantitation of approximately 140 ng g(-1). Evaluation of field samples by SPME-GC/MS detected considerably higher levels of MC, than detected by conventional methods (i.e. ELISA), and it is proposed that this technique reveals MC (particularly in the bound form) that is not detected by these methods. These results indicate that the developed method provides improved detection capability for MC in biological matrices, and will enhance our ability to understand bioaccumulation in freshwater food webs, as well as monitor exposure.

Dispersive liquid-liquid microextraction (DLLME) has been developed for the extraction and preconcentration of diethofencarb (DF) and pyrimethanil (PM) in environmental water. In the method, a suitable mixture of extraction solvent (50 μL carbon tetrachloride) and dispersive solvent (0.75 mL acetonitrile) are injected into the aqueous samples (5.00 mL) and the cloudy solution is observed. After centrifugation, the enriched analytes in the sediment phase were determined by HPLC-VWD. Different influencing factors, such as the kind and volume of extraction and dispersive solvent, extraction time and salt effect were investigated. Under the optimum conditions, the enrichment factors for DF and PM were both 108 and the limit of detection were 0.021 ng mL(-1) and 0.015ng mL(-1), respectively. The linear ranges were 0.08-400ng mL(-1) for DF and 0.04-200ng mL(-1) for PM. The relative standard deviation (RSDs) were both almost at 6.0% (n = 6). The relative recoveries from samples of environmental water were from the range of 87.0 to 107.2%. Compared with other methods, DLLME is a very simple, rapid, sensitive (low limit of detection) and economical (only 5 mL volume of sample) method.

This work is a thorough investigation on the major operating parameters of the programmable temperature vaporization (PTV) inlet used for gas chromatographic injection, including injection mode and volume, inlet temperature, vent and purge flow rates. The results clearly demonstrate the advantage of large volume injection in enhancing the detection of polybrominated diphenyl ethers (PBDEs). Partial loss of injected PBDEs occurred during solvent venting and due to incomplete sample transfer. Such loss was minimized by lowering the initial inlet temperature and vent flow and elevating the final inlet temperature. The results show that 50 mL/min vent flow, as low as 0 degrees C initial and higher than 300 degrees C final inlet temperatures produced the relatively high responses. Two mass spectrometric parameters were also evaluated. Indoor dust, lake sediment and human placenta tissue samples were analyzed to demonstrate reliability and sensitivity improvement of the PTV large volume injection.

The aim of the present study was to develop a new analytical method of chromatographic determination of two important markers of ETS exposure: nicotine and 3-vinylpyridine (3-ethenylpyridine, 3-EP) in mainstream (MS) and sidestream (SS) smoke of one single cigarette and in indoor air using direct solid phase extraction combined with gas chromatography. The method can be utilised for both nicotine and 3-EP determination in SS and MS of one single cigarette as well as it allows for a precise determination of compound distribution in indoor air. The application of the same analytical method for both kinds of samples allows anticipating indoor air distribution of both analysed compounds in a very precise way. The precision of the method (calculated as a relative standard deviation) was 9.78% for nicotine and 2.67% for 3-EP; whereas the accuracy (evaluated by a recovery study conducted at three different levels) was 70.1 and 87.3%, respectively. The limit of detection was 0.06 µg per cigarette for both nicotine and 3-EP. The method was evaluated by determining the compounds of interest in two commercially available brands of cigarettes as well as in the reference cigarettes 3R4F and also in indoor air polluted with tobacco smoke. Determined levels of compounds of interest in MS varied from 586 to 772 (nicotine) µg per cigarette and from 3.5 to 10.7 (3-EP) µg per cigarette. In SS smoke the level varied from 14,370 to 22,590 (nicotine) µg per cigarette and from 185 to 550 (3-EP) µg per cigarette, whereas levels in indoor air polluted with tobacco smoke varied from 50.1 to 157.3 (nicotine) µg m(-3) and from 7.7 to 20.8 (3-EP) µg m(-3).

Protocols are described for constructing laboratory micro-ecosystems (MES), incubating them with radiolabelled pesticides and then using a routine test procedure to ascertain the fate of these pesticides in surface water. The performance of fresh ecocores and acclimated MES from two sources was compared. The influence of the duration of the acclimation to room temperature and a light cycle on the fate of parathion was studied. The variation between replicates of MES was less than that between ecocores. The eutrophic ecocores and MES performed similarly, the oligotrophic ecocores transformed parathion faster than the oligotrophic MES. In eutrophic systems, reduction to aminoparathion was much faster than in oligotrophic systems. The sandy oligotrophic MES needed a longer acclimation to laboratory conditions than the eutrophic MES to produce reproducible results. The results of year-to-year experiments were also more reproducible for the eutrophic MES.

Water samples from Llobregat river entering two water work plants, Barcelona tap water and waste dumping samples taken along the river course were analyzed for trace organic contaminants by different procedures, liquid-liquid extraction, adsorption on granular activated carbon followed by GC/MS/DS. Ether insoluble organic fractions were analyzed and fractionated by HPLC with diode-array detection, followed by FAB and FAB-CID-MIKE characterisation. Results, after two years monitoring, proved that surfactants, plasticizers, ethyleneglycol derivatives, phosphates, hydrocarbons and other miscellaneous compounds can be considered as chronic pollutants of Llobregat river. Some of the identified compounds by GC/MS and FAB mass spectrometry have not been previously reported to occur in water.

The atmospheric transport of organic pollutants over long distances and their effect on the biological cycles of the sea are two major questions of concern in environmental chemistry. These processes are of particular importance in the Mediterranean Sea because of its semi-enclosed characteristics, which determine the accumulation of the pollutants entering into the system. In order to get some insight into these processes a project (PHYCEMED), was developed for the evaluation of the atmospheric budget of organic and inorganic substances in the Western Mediterranean and for the investigation of the exchange mechanisms of these materials across the air/sea interface. A high volume air sampling system including a cascade impactor was placed on board of the R/V le Suroit for collecting the aerosols along several transects parallel to the French, Spanish and North-African coasts, facing areas of different population densities and industrial activities. The cruise was realised on October 1983 and the particulate material was fractionated into the following sizes: 7.2, 3.0, 1.5, 0.96, and 0.03 micron. Quantitative and qualitative analyses of the aliphatic and the aromatic hydrocarbons present in these fractions were performed by high resolution gas chromatography and gas chromatography-mass spectrometry.

A study was conducted in Antigonish, Nova Scotia, to determine the extent to which acid rain related pollutants are present in indoor ambient air. The pollutant study included: fine (0 to 2.5 micron) and coarse (2.5 to 10 micron) particulates, sulphates, nitrates, acidity (H2SO4 and HNO3), SO2 and NO2. During the 3 1/2 month study, maximum levels of 173n equivalent/m3 fine sulphate and 55 n equivalent/m3 H2SO4 were recorded for outdoor air within the town site compared to corresponding values of 110 n equivalent/m3 and 13 n equivalent/m3 for indoor air. Based on back trajectory analysis, wind direction, and sulphuric acid content, it was postulated that local or medium range pollution sources are predominant in the winter while long range transport originating from the United States produces the major episodes when SW winds are persistent.

The anticholinesterase, soman, (CH3)3CC(H)CH3O(CH3)P(O)F, consists of four stereoisomers assigned as C(+/-)P(+/-)-soman in which C stands for chirality in the pinacolyl moiety and P for chirality at phosphorus. The four stereoisomers are separated by gas chromatography on an optically active Chirasil-Val column, synthesized and coated in house, or on a Chirasil-Val column identical with the commercially available column when combined with a Carbowax 20M column. This method in combination with an assay based on acetylcholinesterase inhibition shows that the two isomers which do not have anticholinesterase activity, i.e. C(+/-)P(+/-)-soman, are rapidly degraded in rat blood due to hydrolysis by phosphorylphosphatases. Epimeric soman isomers, e.g. C(+/-)P(-)-soman, can be separately assayed on a Carbowax or a CPSil 8 column, using 2H-labeled soman isomers as internal standards. 2H-labeled soman stereoisomers serve as internal standards in GC-assay of all four stereoisomers on Chirasil-Val. For work-up of the four stereoisomers from rat blood the sample is first stabilized by acidification to pH 4.2 at 0 degree C to suppress hydrolysis by phosphorylphosphatases, addition of aluminum ions for complexation of fluoride ions to prevent regeneration of C(+/-)P(-)-soman by free fluoride ions from soman-inhibited carboxylesterase, and addition of (CH3)3CCH2O(CH3)P(O)F to occupy covalent binding sites for C(+/-)P(-)-soman, before extraction with a Sep-Pak C18 cartridge and elution with ethyl acetate. Using a splitless or on-column injection technique and alkali flame ionization detection, the minimum detectable concentration is 30 pg/3-ml blood sample.

The fate of an experimental oil pollution of intertidal sediments in a sheltered beach of North Brittany (France) has been investigated over a 16-month period. Chemical treatments were applied to two of the three contaminated plots by pre-mixing oil respectively with dispersant and biodegrading agents. The physico-chemical and bacteriological characteristics of the polluted areas were followed with the purpose of identifying the limiting parameters for oil microbial degradation and the effect of treatment. The concentration of hydrocarbons in the oiled sediments did not change significantly during the experimental period. Spectrofluorimetric and chromatographic data showed that the main evolution of oil concerns the degradation of n-alkanes and the removal of light aromatics. Biodegradation of hydrocarbons occurred at a measurable rate only during the warm seasons (average temperature 18 +/- 2 degrees C) causing after sixteen months the disappearance of more than 80% of the n-alkanes fraction independently of the pollution sediment level and the chemical treatment of the experimental plots. However, the biodegradation of n-alkanes proceeded during the first months, at different rates, inversely depending on oil content in the collected samples. The main limiting factor is dissolved oxygen according to the fact that spilled oil was located at 3-5 cm depth in a poorly oxygenated zone characterized by low redox potential. Nutrients were not a limiting factor probably due to domestic and agricultural inputs in this area. A marked bacterial growth was observed two weeks after the oil spill with a relative increase in hydrocarbon degrading bacteria with respect to total heterotrophs. Degradation rates, based on C14 n-hexadecane experiments, seem to follow the same way than specific bacterial counts (plate technique). Specific bacteria are always high at the end of our 16 months' field experimentation. In the laboratory as well as in the field experiments, the same behaviour of untreated and chemically treated oil was observed in partially anaerobic sediment.

A number of different products suspected to contain flame retardants were analysed. TDCP was found in 11 out of 104 samples. It was most common in polyurethane products such as sound absorbing materials and liners for cars and buses. To get an integrated picture of TDCP exposure the contents of vacuum cleaner bags from two homes were analysed. One of these contained TDCP. To investigate possible presence in humans, blood samples were analysed. For clean-up, Sep-Pak cartridges with C18 phase were used. These cartridges contained TDCP and it was not possible to eliminate this background entirely. The NCIMS detection sensitivity for TDCP was better when analysing plasma extracts than when analysing pure standard solutions. Thus quantitative determinations of TDCP must be made by standard additions to plasma extracts. Something in the blood plasma seems to be able to bind or immobilise a certain amount of TDCP. Therefore it was not possible to analyse amounts less than 600 pg/ml whole blood with this method. None of the 37 analysed blood samples exceeded this value.

An analytical procedure for determining methyl- and ethylmercury (MeHg/EtHg) in natural waters is described. MeHg/EtHg was preconcentrated from water on a sulfhydryl cotton fiber (SCF) adsorbent and eluted with a small volume of a mixture of 1 M hydrochloric acid and 2 M sodium chloride. The eluate was extracted with benzene. The measurements of MeHg/EtHg in benzene extract were determined by gas chromatography with electron capture detector. The detection limit for MeHg/EtHg was about 0.04 ng L-1 using a 20 L water sample. The precision was about 20%. The application of the proposed method to one snow and four freshwater samples varying in humus content is described. The MeHg concentrations found in different freshwater samples were ranged from 0.09 to 0.22 ng L-1 and the recoveries of spiked MeHg were ranged from 42 to 68% which were strongly correlated to the content of humic substances. The MeHg concentration found in snow was 0.28 ng L-1 and the recovery was 79%. The analytical results of MeHg concentration in freshwater samples are discussed in relation to the pH used in the preconcentration, the humus content, the fraction of methylmercury in organic bound mercury and mercury in fish.

'Voodoo' is a new substance of abuse that recently spread among youth in Egypt. It has numerous potentially dangerous effects on humans. However, to date the composition of the main constituents of this compound is unknown.

Several reaction principles can be used for the detection of organophosphorous compounds. E.g. the "molybdenum blue" method, the colorimetric and fluorimetric variants of the Schoenemann reaction, electrochemical detection of cyanides upon reaction with certain oximes, photoemission of exitated HPO molecules in a hydrogen rich flame and the well known enzymatic detection of cholinesterase inhibiting compounds. Various detection systems have been developed varying from simple, manually operated devices to more sophisticated and continuous functioning detectors. These well established detection principles and some new emerging techniques, like microsensors using the surface acoustic wave technique, will be discussed.

Exposures to beryllium (Be), even at extremely low levels, can cause severe health effects in a percentage of those exposed; consequently, occupational exposure limits (OELs) promulgated for this element are the lowest established for any element. This work describes the advantages of using highly alkaline dye solutions for determination of Be in occupational hygiene and environmental samples by means of an optical molecular fluorescence technique after sample extraction in 1-3% (w˖w) aqueous ammonium bifluoride (NHHF). Improved attributes include the ability to further enhance the detection limits of Be in extraction solutions of high acidity with minimal dilution, which is particularly beneficial when NHHF solutions of higher concentration are used for extraction of Be from soil samples. Significant improvements in Be method detection limits (MDLs) are obtained at levels many-fold below those reported previously for this methodology. Notably, MDLs for Be of <0.01 ng l / 0.1 ng per sample have been attained, which are superior to MDLs routinely reported for this element by means of the most widely used ultra-trace elemental measurement technique, inductively coupled plasma mass spectrometry (ICP-MS). Very low MDLs for Be are essential in consideration of reductions in OELs for this element in workplace air by health organizations and regulatory agencies in the USA and internationally. Applications of enhanced Be measurements to air filter samples, surface wipe samples, soils and newly-designed occupational air sampler inserts are illustrated.

Portable instruments based on X-Ray Fluorescence Spectrometry (XRF) have the potential to assist in field-based studies provided the data produced are reliable. In this study, we evaluate the performance of two different types of XRF instrument (XOS prototype, and Thermo Niton XL3t). These two XRF analyzers were evaluated in a laboratory setting, and data were reported for 17 elements (As, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, Sn, Sr, Ti, V, and Zn). Samples analyzed (n=38) included ethnic herbal medicine products (HMP), ethnic spices (ES), and cosmetic products (CP). Comparison analyses were carried out using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). In general, results reported for Cd, Cu and Pb by the XOS prototype analyzer, and based on the instrument's non-metal mode, were negatively biased (5 % to 95 %) compared to ICP-OES. In contrast, results reported for Pb, As, Cd, Cu and Zn by the Niton, based on using the soil mode, were positively biased, in some instances (Cd) by up to 4 orders of magnitude. While the sensitivity of both instruments was insufficient for reliably "quantifying" toxic elements below 15 mg/kg, XRF was still capable of positively "detecting" many elements at the low single digit mg/kg levels. However, for semi-quantification estimates of contaminants at higher levels, and with limited sample preparation, both XRF instruments were deemed fit for the purpose. This study demonstrates that modern XRF instrumentation is valuable for characterizing the elemental content of food, cosmetic, and medicinal products. The technology is particularly useful for rapidly screening large numbers of products (100s per day) in the field, and quickly identifying those that may contain potentially hazardous levels of toxic elements. Toxic elements can be confirmed by examining the raw spectrum, and the limitations of factory-based calibration are generally manageable for field-based studies.

Emerging concerns regarding the toxicity of inhaled wood dust support the need for techniques to quantitate wood content of mixed industrial dusts. The diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) analysis technique was applied to the determination of wood content of 181 inhalable dust samples (geometric mean concentration: 0.895 mg/m(3); geometric standard deviation: 2.73) collected from six wood product industry factories using 25mm glass fibre filters with the Button aerosol sampler. Prior to direct DRIFTS analysis the filter samples were treated with ethyl acetate and re-deposited uniformly. Standards ranging from 125 μg to 4000 μg were prepared for red oak, southern yellow pine, and red cedar and used for quantitation of samples depending upon the wood materials present at a given factory. The oak standards spectra were quantitated by linear regression of response in Kubelka-Munk units at 1736 cm(-1), whereas the pine standards and the cedar standards spectra were quantitated by polynomial regression of response in log 1/R units at 1734 cm(-1), with the selected wavenumbers corresponding to stretching vibration of free C=O from cellulose and hemicelluloses. For one factory which used both soft- and hardwoods, a separate polynomial standard curve was created by proportionally combining the oak and pine standards polynomial regression equations based on response (log 1/R) at 1734 cm(-1). The analytical limits of detection were approximately 52 μg of oak, 20 μg of pine, 30 μg of cedar, and 16 μg of mixed oak and pine for the factory with mixed woods. Overall, the average of dry wood dust percentage of inhalable dust was approximately 56% and the average dry wood dust weight was 0.572mg for the Button samples. Across factories, there were statistically significant differences (p<0.001) for the percentage of dry wood dust in inhalable dust with factory averages ranging from 33.5 to 97.6%.

A simple, quick and sensitive procedure is described to monitor urinary clearance of aromatic amines in industrial workers. Estimation is based on the measurement of coloured Schiff's bases developed with 4-dimethylaminocinnamaldehyde-organic acid reagent. Extraction of amines in water saturated butanol ensured 89-97% recovery from biological samples with a coefficient of variation of less than 8%. Regression analyses of the absorbance-concentration curves with different aromatic amines showed excellent correlation coefficient and a high molar absorptivity with the lowest detection limits ranging between 0.05-0.12 microgram ml-1. The proposed reagent has additional use as a spray reagent to detect amine spots on chromatograms. Low final acidity ensures estimates of free amines without causing hydrolysis of conjugated amines.

Heavy metals were leached from various polluted soils by selective extraction reagents (water, BaCl2, acetate buffer + EDTA, HNO3) in order to establish the distribution of the chemical species of Cd, Zn, Cu and Pb. The leachates were directly injected into a plasma spectrometer in order to analyse immediately the extraction solution. This continuous on-line analysis gives qualitative information about the chemical behaviour of each element in function of the type of soil. It permits also to modify the extraction procedure for each sample studied by adjusting the volume of the extraction solution, the time of extraction, or by choosing another extraction reagent more adapted to the sample. The sum of the respective fraction is in rather good agreement with the total analysis of the soil.